A big exam is held every three years to judge the talents of scholars all over the world and select some outstanding talents to serve the Ming Dynasty. However, in an imperial examination in Zhu Yuanzhang's later years, all the scholars on the list came from the south, and none from the north was selected. When the imperial list came out, the northern scholars were furious and thought that someone was operating behind the scenes, and there was a big shady inside. Northern scholars poured into the yamen together, claiming that the exam discriminated against northern scholars. Zhu Yuanzhang immediately investigated the matter after hearing about it, but after a thorough investigation, he found that there was no derailment.
Zhu Yuanzhang instructed the examiner to change his original marking score. Several northerners were added to the list to quell the political incident, but the examiner at that time thought that his judgment was correct and did not change his original intention. Zhu Yuanzhang had no choice but to demote the examiner to Shu Ren, which temporarily calmed the anger of northern scholars. Zhu Yuanzhang personally presided over the imperial examination, and finally all the people on the list were northern scholars.
In order to avoid this extreme phenomenon and to avoid calming the anger of scholars all over the world. Zhu Yuanzhang decided to divide the imperial examinations into the South List and the North List, with the southern Jinshi participating in the South List and the northern Jinshi participating in the North List. Every year, there must be southerners and northerners who are selected in the imperial examination. This method of selecting scholars from the north and the south temporarily solved the immediate problem, and other successors also followed this system.